Grass Seed Calculator

Estimate the grass seed you need based on lawn size and whether you’re seeding new or overseeding.

Check the bag for its recommended application rate — rates vary by grass variety.

Your info stays on your device. We don’t store anything.

How to measure a lawn

Split the lawn into rectangles and add their areas. Pace it off if you don’t have a tape — an average stride is close to 2.5 feet.

How we calculated it

Seed rates are quoted in pounds per 1,000 square feet, so we compute your lawn’s area, divide by 1,000, and multiply by the rate on your bag. New lawns use roughly double the overseeding rate.

Things that can change your result
  • Rates differ by species: tall fescue seeds far heavier than Kentucky bluegrass.
  • Coated seed weighs more per seed — follow the bag’s rate for coated products.
  • Shade mixes, sun mixes, and repair blends each quote their own coverage.
Buying tips
  • The bag’s recommended rate beats any generic table — including ours.
  • More seed isn’t better: overcrowded seedlings compete and thin out.
  • Split the seed in half and spread in two perpendicular passes for even coverage.
Common mistakes
  • Using a new-lawn rate to overseed (or vice versa).
  • Seeding without soil contact — rake first, seed, then rake lightly again.
  • Ignoring the seeding season for your grass type.
Frequently asked questions

How much grass seed for 1,000 square feet?

Typically 6–8 lb for a new tall-fescue lawn, or about half that when overseeding — but the rate on your bag wins.

What’s the difference between new-lawn and overseeding rates?

Overseeding adds seed to existing turf, so it needs roughly half the density of starting from bare soil.

Can I just spread extra seed to be safe?

A little extra is fine; double-rate seeding backfires as seedlings compete for light and water and thin themselves out.